JPH1199449A - Noncontact temperature distribution measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a noncontact temperature distribution measuring device capable of measuring two-dimensional temperature distribution of a surface of a cutting tool without receiving influence of chips, etc., produced from a cutting material in the middle of cutting work. SOLUTION: A cutting material 6 has a cutting surface to be cut by a cutting tool 8 and a cutout part 12 to temporarily make the cutting tool 8 in a noncontact state. A picture image during a period to be in an exposed state as the cutting tool 8 passes through this cutout part 12 is picked up by a camera mechanism 2 while moving it by specified delay time t. A plural number of picture image information provided by this image pick-up has temperature change information of each portion at the time when the cutting tool 8 gradually passes through the cutout part 12 from the point of a moment to intrude into it. Consequently, the picture image information is arranged in correspondence with exposure passing time from the aforementioned point of the moment, and two-dimensional temperature distribution of the cutting tool 8 at the aforementioned point of the moment is computed in accordance with change tendency of the picture image information.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-contact temperature distribution measuring device for measuring a two-dimensional temperature distribution of a cutting tool in a non-contact state during cutting.

[0002]

2. Description of the Related Art As an apparatus for measuring the surface temperature of an object in a non-contact manner, a far-infrared image forming apparatus (thermograph) for capturing a far-infrared image radiated from the object surface is generally known.

[0003]

However, this far-infrared image forming apparatus measures the temperature distribution on the surface of an object to be measured. For this reason, there is a problem that the cutting tool is hidden by the chips generated from the work material during the cutting process, and it is not possible to measure the two-dimensional temperature distribution of the cutting edge of the cutting tool or the rake face of the cutting edge.

[0004] A temperature measuring method called a single bite method in which a thermocouple is embedded in a cutting tool and the temperature of the cutting tool is measured by the thermocouple is known. In this method, a cutting tool is used. Cannot measure the two-dimensional temperature distribution in a relatively wide range. Further, in this method, it is necessary to form a hole, a groove, or the like for embedding a thermocouple in the cutting tool, so that there is a problem that the mechanical strength of the cutting tool is reduced. In addition, there is a problem that complicated pretreatment for forming such holes and grooves is required.

The present invention has been made in view of such problems of the prior art, and more simply and accurately measures a two-dimensional temperature distribution of a cutting tool during a cutting process in a non-contact state. It is an object of the present invention to provide a non-contact temperature distribution measuring device that can perform the measurement.

[0006]

According to the present invention, there is provided a non-contact temperature distribution measuring apparatus for measuring a two-dimensional temperature distribution of a cutting tool during cutting, wherein the cutting tool and a workpiece are separated during the cutting. Cutting state setting means for setting a substantial cutting period by contacting and a substantially non-cutting period by separating the cutting tool and the work material; and for each predetermined delay time, the cutting tool Imaging means for imaging a plurality of times, and a plurality of image information obtained by the imaging means a plurality of times, for each piece of information corresponding to the same part of the cutting tool, corresponding to the elapsed exposure time from the switching time In addition, a change characteristic calculating means for calculating a change tendency of the image information with respect to the exposure elapsed time, and a cutting tool at the time of the switching based on the change tendency calculated by the change characteristic calculation means. And configured to include a temperature distribution calculating means for calculating a dimension temperature distribution.

[0007]

A plurality of exposure image information of the cutting tool can be obtained by imaging the cutting tool a plurality of times at each of a plurality of different delay times based on the switching point detected by the sensor means. By associating the plurality of pieces of image information with the exposure elapsed time from the switching time for each piece of information corresponding to the same part of the cutting tool, a tendency of the temperature change of the exposed cutting tool can be obtained. By calculating the temperature of the cutting tool at the time of the switching based on this change tendency, when the cutting tool is in contact with the work material, that is, a two-dimensional temperature distribution of the cutting tool during the cutting is obtained. .

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to FIGS. In these drawings, the same or equivalent components are denoted by the same reference numerals.

FIG. 1 is a block diagram showing a configuration of a non-contact temperature distribution measuring apparatus according to an embodiment, and FIG. 2 is a diagram showing an example of an installation mode of the present apparatus on an object to be measured.

In FIG. 1, the apparatus includes an imaging unit for imaging an object to be measured and an analysis unit for analyzing an image signal S _AW output from the imaging unit to obtain a two-dimensional temperature distribution of the object to be measured. Have.

As shown in FIG. 2, the image pickup unit includes a camera mechanism 2 for picking up an image with a two-dimensional image pickup device, and an optical sensor 4 composed of a phototransistor or the like.

The camera mechanism 2 and the optical sensor 4 are arranged at appropriate positions with respect to the object to be measured. For example, as shown in the figure, when performing cutting using various lathe devices,
When measuring the two-dimensional temperature distribution of the cutting edge and the rake face of the cutting tool 8 for cutting the peripheral side wall of the work material 6 rotating in the circumferential direction θ, the camera mechanism 2 uses the imaging range (one point). The cutting tool 8 to be measured is arranged so as to fall within the field of view indicated by the dashed line AW), and the optical sensor 4 is arranged toward the peripheral side wall of the workpiece 6.

Incidentally, in order to prevent a problem such as chips generated from the work material 6 during the cutting process from scattering and contaminating the imaging surface of the camera mechanism 2, the imaging optical system in the camera mechanism 2 is prevented. The system has a focal length of 50 mm or more and a resolution of 30 μm.
It is designed so that the following values of optical characteristics can be obtained.
Here, the resolution means the limit value of the detail reproduction ability,
For example, when an evenly spaced black and white stripe pattern is imaged, at the limit point where they can be imaged separately.
It is defined as the minimum black stripe interval. More preferably, the focal length is 100 mm or more, and the resolving power is 2 mm.
It is desirable to set the resolution higher than 5 μm (resolution: ≦ 25 μm).

Furthermore, during the cutting operation, a substantial cutting period due to the contact between the workpiece 6 and the cutting tool 8 and a substantial non-cutting time due to the separation between the workpiece 6 and the cutting tool 8. As a cutting state setting means for setting the notch 1 inside the cut surface 10 to be cut by the cutting tool 8.
2 is used. Therefore, when the work material 6 rotates in the circumferential direction θ, the cutting tool 8 is separated from the work material 6 when passing through the notch 12, so that the cutting is temporarily stopped, and the cutting edge and the cutting edge of the cutting tool 8 are cut. The rake face is exposed.

As shown in FIG. 3, the camera mechanism 2
Horizontal line direction j of the built-in two-dimensional imaging device
And the rotation direction (circumferential direction) θ of the work material 6 is disposed so as to be substantially orthogonal. As a result, the work material 6 becomes the first (i
= 1), it moves within the imageable range AW along the vertical line direction i from the horizontal line side.

The shape and size of the notch 12 may be arbitrary. In short, any shape may be used as long as the cutting tool 8 is separated from the work material 6 during the cutting process and a state in which the cutting process is not substantially performed.

In FIG. 1, the analysis unit has a control unit 14 having an arithmetic control function and a microprocessor (MPU) for controlling the operation of the entire analysis unit.
And an imaging control unit 16 for controlling an imaging operation of the camera mechanism 2
And an image processing unit 18 for obtaining a two-dimensional temperature distribution on the surface of the cutting tool 8 based on an image signal S _AW output from the camera mechanism 2, and an external device such as an external display device, an external storage device, and a keyboard. Input / output port 20 for each of these components, and these components 14 to 20 are connected via a so-called bus line BUS.

The imaging controller 16 includes a synchronization detector 22 and
A measurement condition setting unit 24, a measurement condition storage memory 26, and a driving unit 28 are provided.

The synchronization detecting unit 22 determines when the cut surface 10 is switched to the notch 12 based on the change in the amplitude of the light detection signal _SPD output from the optical sensor 4 while the work material 6 is rotating. (Hereinafter referred to as a first synchronization time point) t _F and a time point at which the cut-out portion 12 is switched to the cut surface 10 (hereinafter referred to as a second synchronization time point).
T _E ).

FIG. 4 is a timing chart showing the operation of detecting the first synchronization time point t _F and the second synchronization time point t _E by the synchronization detection unit 22. In the figure, the amplitude of the light detection signal _SPD output from the optical sensor 4 changes between when the cut surface 10 is received and when the notch 12 is received. By differentiating the photodetection signal S _PD, it generates a pulse-like differential waveform signal [Delta] S _PD. Furthermore, the differential waveform signal [Delta] S _PD threshold T pulse waveform on the negative side is in a predetermined
The first synchronizing signal Sout which becomes logic “H” at the point of time exceeding HD2 and the plus-side pulse waveform change to a predetermined threshold value THD1
, A second synchronizing signal Sin which becomes logic "H" at the time when the threshold value is exceeded is formed. Then, it is determined that the time when a logic "H" of the first synchronization signal Sout first synchronization time point t _F, the point at which a logic "H" of the second synchronization signal Sin second synchronization time point t _E .

The measuring condition setting section 24 makes the work material 6 make one rotation based on the first and second synchronization time points t _F and t _E set by the first and second synchronization signals Sout and Sin. a time T ₀ required for a rotation speed V of the workpiece 6, and the transit time T _W required for the notch 12 in front of the light sensor 4 passes,
The transit time T _S required for the cut surface 10 to pass in front of the optical sensor 4 and the width W of the notch portion 12 in the circumferential direction θ are obtained.

Further, by dividing this period T _W by the number N of frames to be imaged within the period required for the cutting tool 8 to pass through the cutout portion 12 (ie, T _W ), it becomes a reference for shutter timing. Reference delay time Δ (= T _W / N)
Ask for. The number of frames N can be arbitrarily set by the operator.

The measurement condition data T ₀ , V, T _W , T _S , W, N,
Δ is stored in the measurement condition storage memory 26 and is used when the image processing unit 18 described later calculates a two-dimensional temperature distribution.

Whenever the drive unit 28 detects the time point (first synchronization time point) t _F at which the first synchronization signal Sout output from the synchronization detection unit 22 becomes logic “H”, the drive unit 28 determines the time T _S as a reference. A delay time τm (= m) obtained by adding a time that is an integer m times the delay time Δ
T _S + mΔ) supplies a shutter signal S _T to the camera mechanism 2 when has elapsed. The time T _S is an offset period from when the optical sensor 4 detects the time point t _E to when the cutting tool 8 enters the notch 12. That is, the time T _S is obtained by dividing the offset interval between the optical sensor 4 and the cutting tool 8 by the rotation speed V of the workpiece 6.

[0025] When the delay time τm reaches the time T _S + N × Δ, resets the delay time time τm again, while sequentially increased from the reference delay time delta, set the shutter timing of the camera mechanism 2 Process is repeated.

By causing the camera mechanism 2 to perform an image pickup operation while variably controlling the delay time τm as shown in FIG.
(E ') corresponding to the relative positional relationship between the work material 6 and the cutting tool 8 shown in (a) to (e) of FIG.

In FIG. 1, A / A
D converter 30, temperature compensator 32, measurement range extractor 34,
Exposure elapsed time determination unit 36, temperature change characteristic calculation unit 38, temperature distribution calculation unit 40, image synthesis unit 42, captured image memory 4
4, a temperature change characteristic memory 46 and a composite image memory 48 are provided.

The A / D converter 30 converts the image signal S _AW captured and output by the camera mechanism 2 into digital image data D _AW for each of the delay times τm, and outputs a frame image corresponding to each of the delay times τm. The file is stored in the captured image memory 44 as a file.

The temperature compensator 32 _{converts the} digital image data D _AW representing the luminance component stored in the captured image memory 44 into
It is converted into digital image data (hereinafter, referred to as temperature image data) TD _AW representing a temperature component. Then, it is stored in the captured image memory 44 again as a frame image file associated with each delay time τm. Here, each pixel data P _{i, j} constituting the digital image data D _AW (where 1 ≦ i
≦ I, 1 ≦ j ≦ J) to obtain the temperature image data TD _AW of the temperature component by applying the Stefan-Boltzmann equation of the following equation (1).

Ω = εσT ⁴ (1) where ω is infrared energy (corresponding to the luminance of each pixel data P _{i, j} ), and T is the absolute temperature of the object (corresponding to each temperature pixel data TP _{i, j} ) ), Ε is the emissivity (ε ≦ 1), and σ is the Stefan-Boltzmann constant.

The measurement range extracting section 34 is provided with
Temperature image data T for a plurality of frame images stored in
From D _AW, the cutting tool 8 to extract the temperature image data TR _B corresponding to a period which does not substantially cutting, it is stored in the composite image memory 48. That is, of the temperature image data TD _AW , data of an image in which the cutting edge and the rake face of the cutting tool 8 are hidden by the chips generated during the cutting process are not extracted. through the 12 extracts the temperature image data TR _B obtained when substantially cutting is not performed. By this process, the temperature image data TR _B representing the image of the cutting tool 8 exposed without being obstructed by the chips are extracted.

[0032] FIG. 6 is a diagram showing the extraction principle of temperature image data TR _B. With respect to the temperature image data TR _AW of each frame image file, a group of pixels (for example, Q ₁ -Q _{1 in} FIG.
Examining a pixel group located on the line, the temperature change distribution of temperature pixel data obtained from the pixel group) located in the Q ₂ -Q ₂ line. Q ₁
-Q ₁ from a change in the temperature image data on a line of the pixel group, and detects the range W _B of the notch 12, the cutting tool 8 to the range W in _B
Is present, the temperature image data TR _AW is extracted to obtain the pixel temperature data TR representing the cutting tool 8 that is not hidden by the chips.
_{Get B.}

As described above, the range W _B of the notch 12 is
And detecting, by extracting only the temperature image data data TR _AW present in the range W in _B, with removal temperature image data corresponding to the non-cutting surface 10 or the like of the workpiece 6, hidden by chip it may be obtained a pixel temperature data TR _B which represents the non cutting tool 8.

The exposure elapsed time judging section 36 is imaged by the camera mechanism 2 from the point (moment) when each part of the cutting tool 8 hidden by the chips passes through the notch 12 and becomes exposed. elapse before (hereinafter, exposure of the elapsed time) tau, is calculated based on the temperature image data TR _B each.

The principle of calculating the exposure elapsed time τ will be described with reference to FIGS. As described with reference to FIG. 3, the image of the work material 6 moves along the vertical line direction i of the two-dimensional imaging device built in the camera mechanism 2.
Therefore, the cutting tool 8 moves relative to the workpiece 6 in the opposite direction. From this relationship, as shown in FIG. 7, the portion of the notch 12 farther from the front edge portion E has a longer exposure elapsed time τ. For example, the exposure elapsed time τ at the same specific portion x shown in FIG. 7 becomes gradually longer as the state moves from FIG. 7A to FIG. 7C.

Therefore, as shown in FIG. 7, a plurality of temperature image data TR _B (1) to TR _B (N) having the temperature pixel data TP _{i, j} of the specific portion x are stored in the composite image memory 48. reading, the temperature image data TR _B (1) ~TR in _B (N), the horizontal line corresponding to a previous edge portion E of the notch 12 I _E (1) ~I
_E (N) and the temperature pixel data TP _{i, j} corresponding to the specific portion x
Detecting the horizontal line I _F to the position of _{(1) ~I F (N)} . Furthermore, each of the horizontal lines _{I E (1) ~I E (} N) and _{I F (1) ~I F (} N)
Horizontal line number I _F existing between the _{(1) -I E (1)} , ~, I
Calculating the _{F (N) -I E (N} ). Then, a time δ required to pass through the one horizontal line period of the notch 12 is two-dimensional imaging device, the number of these horizontal lines _{I F (1) -I E (} 1), ~,
By multiplying the _{I F (N) -I E (} N), seeking τ (1) ~τ (N) exposure elapsed time of the specific portion x.

That is, the temperature image data TR _B (1) shown in FIG.
The exposure elapsed time τ (1) of the middle temperature pixel data TP _{i, j} is τ
_{(1) = (I F (} 1) -I E (1)) × δ , and the temperature pixel data TP i temperature image data TR _B (2) _{in, j} exposure elapsed time τ
(2), τ (2) = (I F (2) -I E (2)) × δ , and the so on to the temperature pixel data TP in temperature image data TR _B (N)
_{i, j} exposure elapsed time tau (N) is, τ (N) = (I F (N) -I
_E (N)) × δ. In addition, the exposure elapsed time τ of the remaining temperature pixel data is similarly obtained.

[0038] Note that the time [delta], based on the total horizontal line count I of length L _AW and two-dimensional imaging device in the circumferential direction θ of the rotational speed V and the imaging range AW of the workpiece 8, [delta] = L _AW / (I ×
V).

The temperature change characteristic calculation unit 38 calculates the pixel data TP _{i, j} corresponding to the same part of the cutting tool 8 from the temperature image data TR _B of a plurality of files stored in the composite image memory 48 by the exposure elapsed time τ. (1) Arranged along [tau] (N), and a temperature characteristic curve CPi _{, j} representing a tendency of a temperature change after the portion is exposed is estimated and calculated.

FIG. 8 shows a temperature characteristic curve C for the temperature pixel data TP _{i, j} corresponding to a specific portion of the cutting tool 8.
The calculation principle of P _{i, j} is shown as a representative. In the figure, the temperature pixel data T _B (1) to TR _B (N)
_{P i, j (1) ~TP} i, reads _j (N), these temperatures pixel data _{TP i, j (1) ~TP} i, j (N) exposure time elapsed respective tau (1)
Arrange along .tau. (N). Curve fitting method and minimum 2
A temperature characteristic curve CP _{i, j} representing a change tendency of the temperature pixel data TP _{i, j} (1) to TP _{i, j} (N) is estimated and calculated using statistical processing such as multiplication or a neural network method. In addition, cutting tool 8
By performing the same estimation calculation for the remaining parts, the temperature characteristic curves CP _{i, j} of all the parts are obtained, and the data are stored in the temperature change characteristic memory 46.

The temperature distribution calculating section 40 calculates the instant t when each part of the cutting tool 8 is exposed based on the data of the temperature characteristic curve CP _{i, j} stored in the temperature change characteristic memory 46.
temperature distribution TP _{i, j} a (t _r) is estimated operation in the _r, re stores data of the operation result in the composite image memory 48. Note that the instant t _r each site was the exposure state of the cutting tool 8, the horizontal line I corresponding to a previous edge portion E of the notch 12 shown in FIG. 7
_{It is} obtained from the position information of _E (1) to _IE (N).

The image synthesizing section 42 interpolates the missing part of the data of the temperature distribution TP _{i, j} (t _r ) stored in the synthesized image memory 48 by statistical processing, thereby obtaining the cutting tool 8.
Then, two-dimensional temperature distribution data TSB representing the two-dimensional temperature distribution of the entire surface of is formed and stored in the composite image memory 48.
In addition, the two-dimensional temperature distribution data TSB is also stored in an external storage device via the input / output port 20, reproduced and displayed on an external monitor device, printed on a hard copy, and the like.

Next, a series of operations of the non-contact temperature distribution measuring device will be described with reference to a flowchart shown in FIG.

When the apparatus is started, in step S100, the imaging control unit 16 is operated, and the work material 6
During rotation, the synchronization detection unit 22 and the measurement condition setting unit 24
Calculates various measurement conditions such as the delay reference time Δ and the rotation speed V of the work material 6 based on the light detection signal _SPD of the optical sensor 4. Note that during this process, the image processing unit 18 does not perform the process for obtaining the two-dimensional temperature distribution, and simply outputs the image signal S _AW via the A / D converter 30 and the input / output port 20 to an external display device or the like. Transferred to

When the various measurement conditions are obtained, the flow shifts to step S110, where the image processing section 18 is started. First, in step S120, the image signal S _AW output from the camera mechanism 2 is converted into digital image data D _AW by the A / D converter 30 in synchronization with the delay time τm set by the driving unit 28, and It is stored in the memory 44. Here, imaging processing is performed until digital image data D _AW for a frame image sufficient to obtain a two-dimensional temperature distribution on the surface of the cutting tool 8 is obtained.

When sufficient digital image data D _AW is collected, in step S 130, the temperature compensator 32 converts the digital image data D _AW of the luminance component into the temperature image data TD _AW of the temperature component. Next, step S14
At 0, the measurement range extraction unit 34 extracts the temperature image data TR _B related to the exposed surface of the cutting tool 8 from the temperature image data TD _AW. Next, in step S150, the exposure elapsed time determination unit 36 determines that the temperature image data TR
The exposure elapsed time τ of each part of the exposed surface is determined based on _B. Next, in step S160, the temperature change characteristic calculation unit 38 calculates the temperature characteristic curve CP for each part of the exposed surface.
_{Find i, j} .

In step S170, the temperature distribution calculator 40 calculates the two-dimensional temperature distribution data T at the instant _tr at which the cutting tool 8 is exposed, based on the temperature characteristic curves CP _{i, j.}
Calculate BS. Then, in step S180,
The image synthesizing unit 42 interpolates the missing data of the two-dimensional temperature distribution data TBS into two-dimensional temperature distribution data TSB representing the entire two-dimensional temperature distribution of the cutting tool 8, and a series of the processing ends.

As described above, according to this embodiment, the temperature distribution when the cutting tool 8 passes through the notch 12 is measured, and based on the data of the temperature distribution, the surface 10 to be cut is cut. Since the two-dimensional temperature distribution during cutting is determined by the estimation calculation process, the cutting tool 8
Even if is hidden by the chips, the two-dimensional temperature distribution of the cutting tool 8 can be measured with high accuracy.

In the above description, a configuration has been described in which the imaging control unit 16 is provided with the measurement condition setting unit 24 and the measurement condition setting unit 24 automatically obtains the measurement conditions.
The present invention is not limited to this configuration. For example, when measurement conditions such as the rotation speed V and the delay reference time Δ are known, data of these measurement conditions may be stored in the measurement condition storage memory 26 in advance via the input / output port 20. Good. In this case, the measurement condition setting unit 24 can be omitted.

If the materials of the work material 6 and the cutting tool 8 and the temperature change characteristics when the cutting tool 8 is exposed are known in advance _, the data of the temperature characteristic curve CP _{i, j} is used. Temperature change characteristic storage memory 46 via input / output port 20
May be stored. In this case, the exposure elapsed time determination unit 36 and the temperature change characteristic calculation unit 38 can be omitted. Further, if the data of the temperature characteristic curve CP _{i, j} is stored in the temperature change characteristic storage memory 46, the digital image data D _AW corresponding to one frame image when the cutting tool 8 is in the exposed state can be stored in this temperature characteristic. Curve CP _{i, j}
The only to apply to the data, it is possible to calculate the temperature distribution TP _i at the instant t _r became exposed state of each part of the cutting tool _{8, j} a (t _r). For this reason, the processing time (time required for imaging) for collecting the digital image data D _AW can be shortened, and the two-dimensional temperature distribution can be measured at a higher speed.

Further, when the reference delay time Δ is made equal to a so-called frame period preset in the camera mechanism 2, the imaging control section 16 may be omitted. That is, the synchronization detection unit 22, the measurement condition setting unit 24, the measurement condition storage memory 26, and the drive unit 28 in the imaging control unit 16 shown in FIG. 1 are omitted, and the image processing unit 18 uses this frame cycle as a reference delay time Δ. By performing the above-described image processing, a two-dimensional temperature distribution can be obtained. In this case, the optical sensor 4 can also be omitted.

Further, the configuration in which the camera mechanism 2 having the two-dimensional image pickup device performs the frame sequential image pickup has been described.
A configuration in which line-sequential imaging or point-sequential imaging is performed may be adopted.

FIG. 10 shows an example of the configuration of a camera mechanism that performs line-sequential imaging. In the figure, the work piece 6 is arranged so as to face the work material 6 and has the same direction θ as the rotational direction θ of the work material 6.
i, a rotating mirror 50 that rotates at a constant angular velocity Δi,
A line sensor 52 that receives a light image reflected by the rotating mirror 50 is provided, and supplies an image signal S _AW output from the line sensor 52 to the A / D converter 30 in FIG. Then, the image signal S _AW is converted into digital image data D _AW in units of frame images, _fetched into the captured image memory 44, and the digital image data D _AW is subjected to the above-described image processing by the image processing unit 18, whereby the two-dimensional temperature is obtained. The distribution can be determined.

FIG. 11 shows an example of the configuration of a camera mechanism for performing point-sequential imaging. In the figure, the work piece 6 is arranged so as to face the work material 6 and has the same direction θ as the rotational direction θ of the work material 6.
i, a rotating mirror 54 that rotates at a predetermined angular velocity Δi,
A direction θ orthogonal to the rotation direction θi of the rotating mirror 54
j, a polygon mirror 56 that rotates at a predetermined angular velocity Δj
And a light receiving element 58 such as a phototransistor for receiving the reflected light from the polygon mirror 56.
The image signal S _AW output from 8 is supplied to the A / D converter 30 in FIG. Then, the image signal S _AW is converted into digital image data D _AW in units of frame images, _fetched into the captured image memory 44, and the digital image data D _AW is subjected to the above-described image processing by the image processing unit 18, whereby the two-dimensional temperature is obtained. The distribution can be determined.

As described above, the configuration in which the imaging scan is performed in line-sequential or dot-sequential manner is more effective than the configuration in which plane-sequential imaging is performed.
An inexpensive camera mechanism 2 can be realized.

In the above description, the use mode in which the outer peripheral surface of the work material 6 is cut with the cutting tool 8 has been described, but the present apparatus can be applied to other use modes.

FIG. 12 shows a case in which the cutting tool 8 is used to cut the inner wall of a cylindrical workpiece 60 rotating in the circumferential direction θ using various lathes.

In this case, a notch 62 formed of a slit-like recess or a through hole is formed in a part of the inner wall of the workpiece 60.
Is formed in advance so that the cutting tool 8 is temporarily exposed when passing through the notch 62.
Then, the two-dimensional temperature distribution during cutting of the cutting tool 8 can be measured by taking an image of the cutting tool 8 in the exposed state with the camera mechanism 2 and performing image processing with the image processing unit 18.

As shown in the figure, a thin optical fiber 64 is extended to the camera mechanism 2, and an image of the cutting tool 8 is introduced from the tip end (light incident end) of the optical fiber 64, and an image pickup device is provided. Alternatively, the image may be picked up. By providing the optical fiber 64 in this way, it is possible to measure a two-dimensional temperature distribution of a cutting tool when cutting a minute part or cutting a complicated part.

[0060]

As described above, according to the present invention, a substantial non-cutting period is set during cutting, and image information of a cutting tool that is exposed during this non-cutting period is obtained. The temperature change characteristic of each part of the cutting tool is obtained based on the image information, and the temperature at the moment when the cutting tool is exposed is estimated based on the temperature change characteristic. Since the two-dimensional temperature distribution of the cutting tool is formed from the temperature, even if chips are generated, the influence thereof can be removed and the two-dimensional temperature distribution of the cutting tool can be measured.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a non-contact temperature distribution measuring device according to an embodiment.

FIG. 2 is an explanatory diagram illustrating an example of an installation mode of a non-contact temperature distribution measurement device.

FIG. 3 is an explanatory diagram illustrating the principle of imaging scanning.

FIG. 4 is a timing chart for explaining the principle for synchronizing the measurement object and the imaging scan.

FIG. 5 is an explanatory diagram illustrating an image obtained by performing imaging and scanning in synchronization with a delay time.

FIG. 6 is an explanatory diagram illustrating a principle for extracting image data of an exposed surface.

FIG. 7 is an explanatory diagram illustrating a principle for obtaining an elapsed exposure time.

FIG. 8 is an explanatory diagram illustrating a principle for obtaining a temperature change curve.

FIG. 9 is a flowchart illustrating a series of operations up to obtaining a two-dimensional temperature distribution by the non-contact temperature distribution measuring device.

FIG. 10 is a configuration explanatory view showing a modified example of the imaging unit.

FIG. 11 is a configuration explanatory view showing another modified example of the imaging unit.

FIG. 12 is an explanatory diagram illustrating another application example of the non-contact temperature distribution measurement device.

[Explanation of symbols]

2 ... Camera mechanism, 4 ... Optical sensor, 6,60 ... Work material, 1
0: cut surface, 12, 62: notch, 14: control unit, 1
6 imaging control unit, 18 image processing unit, 20 input / output port, 22 synchronization detection unit, 24 measurement condition setting unit, 26
Measurement condition storage memory, 28 drive unit, 30 A / D converter, 32 temperature compensation unit, 34 measurement range extraction unit, 36
Exposure elapsed time determination unit, 38: temperature change characteristic calculation unit, 40
... Temperature distribution calculation unit, 42 image synthesis unit, 44 captured image memory, 46 temperature change characteristic storage memory, 48 synthesized image memory, 64 optical fiber.

Claims (5)

[Claims] 1. A non-contact temperature distribution measuring device for measuring a two-dimensional temperature distribution of a cutting tool during cutting, wherein a substantial cutting is performed by bringing the cutting tool into contact with a work material during the cutting. A cutting state setting unit for setting a period, a substantial non-cutting period by separating the cutting tool and the work material, and an imaging unit for imaging the cutting tool a plurality of times for each predetermined delay time. A plurality of image information obtained by a plurality of imaging by the imaging unit, for each information corresponding to the same part of the cutting tool,
A change characteristic calculating unit that calculates a change tendency of the image information with respect to the exposure elapsed time in association with an exposure elapsed time from the switching time; and the switching based on the change tendency obtained by the change characteristic calculating unit. A temperature distribution calculating means for calculating a two-dimensional temperature distribution of the cutting tool at a point in time. 2. The imaging device according to claim 1, further comprising: a sensor unit configured to detect a time point at which the cutting operation is switched from the cutting period to the non-cutting time period. The non-contact temperature distribution measuring apparatus according to claim 1, wherein the cutting tool is imaged a plurality of times. 3. Image information obtained by imaging the cutting tool during the non-cutting period is extracted from a plurality of pieces of image information obtained by a plurality of imagings by the imaging means, and the extracted image 2. The non-contact temperature distribution measuring apparatus according to claim 1, further comprising a measurement range extracting unit that causes the change characteristic calculating unit to process information as a plurality of pieces of image information obtained by the plurality of imagings. 3. 4. The non-contact temperature distribution measuring apparatus according to claim 1, wherein the imaging means has an optical fiber for guiding at least an image of the cutting tool to image the cutting tool. 5. The imaging means has a focal length of 50 mm.
2. The non-contact temperature distribution measuring apparatus according to claim 1, further comprising an imaging optical system set to perform imaging with a resolution higher than 30 μm.